Python now verifies SSL certificates and their associated hostnames by default,
which is fantastic. However, it makes things a bit of a pain for users who have
put a self-signed SSL certificate on their Review Board server. This change
adds a command-line flag and config variable for disabling certificate
verification.

Testing Done

Verified that I got the expected error when running on Python < 2.7.9

Set a bogus hostname in my /etc/hosts and tried to post to that server. Saw
that I got an SSL verification error.

Re-ran command with --disable-ssl-verification and saw a login prompt.